Re: [PATCH 1/2] ref-filter: hacky "streaming" mode

From: Jeff King <peff@peff.net>
Date: Sep 7, 2021, 18:01 UTC
Message-ID: <YTeo/dCFfpAIfo3K@coredump.intra.peff.net>
In-Reply-To: <CAOLTT8QbdNBSY95bCa+UNJBqsJEEHbnaKfZLzvN2Qzd-Np8Lqg@mail.gmail.com>

On Tue, Sep 07, 2021 at 01:28:33PM +0800, ZheNing Hu wrote:

Show 6 quoted lines

> > I think it's just because pretty_print_ref() does not take a "flag"
> > parameter for the caller. So it never sees that REF_ISSYMREF is set.
> >
> 
> yeah, pretty_print_ref() does not set the flag, this is a defect of
> pretty_print_ref(), maybe we need to find a way to set this flag.

In general, I think it could take a flag parameter from its caller. But its caller comes indirectly from for_each_tag_name(), which isn't a regular ref-iterator. It would probably need to switch to using read_ref_full() to get the flags.

Show 25 quoted lines

> > I notice that the --verify output also shows the short refname, which
> > makes me wonder if %(symref) would have other bugs there (because it
> > has to re-resolve the ref to come up with the symref destination).
> >
> 
> This may be easy to fix:
> 
> diff --git a/builtin/tag.c b/builtin/tag.c
> index 452558ec95..4be5d36366 100644
> --- a/builtin/tag.c
> +++ b/builtin/tag.c
> @@ -152,11 +152,11 @@ static int verify_tag(const char *name, const char *ref,
>         if (format->format)
>                 flags = GPG_VERIFY_OMIT_STATUS;
> 
> -       if (gpg_verify_tag(oid, name, flags))
> +       if (gpg_verify_tag(oid, ref, flags))
>                 return -1;
> 
>         if (format->format)
> -               pretty_print_ref(name, oid, format);
> +               pretty_print_ref(ref, oid, format);
> 
>         return 0;
>  }

Yeah, I think that would work, although:

  - there's another caller in cmd_verify_tag() which seems to just pass
    whatever was on the command line. It doesn't even resolve the ref
    itself!

  - I suspect people may be relying on the current behavior. The
    original was added to be able to compare the internal tagname to the
    refname. I.e., that:

      git tag -v --format='%(refname) %(tag)' foo

    would show "foo foo". Now that _should_ be "%(refname:strip=2)", I
    think, but we'd probably be breaking scripts. OTOH, it really feels
    like _not_ handing over a real, fully-qualified refname to the
    ref-filter code will mean other things are broken (e.g.,
    ATOM_UPSTREAM is assuming we have a fully-qualified ref).

    I think a backwards-compatible way of fixing it would be to have
    this call hand over the full refname to the ref-filter code, but
    tell it that %(refname) should default to strip=2. And then anybody
    who wants the full name can use %(refname:strip=0).

    It makes the behavior confusing and quirky, but we can't avoid that
    without breaking compatibility.

-Peff